Asaram Bapu was convicted of the 2013 attack on the girl, a devotee at his ashram in Jodhpur, by a court in the city’s jail. He is expected to appeal.
The guru, who is 77, has 400 ashrams around the world where he teaches meditation and yoga.
He is also on trial in another rape case in western Gujarat state.
Jodhpur is on high alert because of concerns there could be violence from the guru’s supporters, reports BBC Hindi’s Priyanka Dubey who is in the city.
The judge delivered his verdict from the city’s jail because of concerns that it could provoke riots.
Two of the guru’s aides were also convicted and given 20-year jail terms. Two more were acquitted.
“Nothing can compensate for the trauma that the victim and the family have gone through,” Utsav Bains, the victim’s lawyer, told NDTV ahead of sentencing.
The security measures come after followers of another guru, Gurmeet Ram Rahim, ran amok after he was found guilty of rape last year. The resulting violence killed 23 people.
What was the case against Asaram?
Asaram was arrested in 2013 after a case of sexual assault was filed against him by two of his followers, who alleged that he had assaulted their daughter.
Police say that the couple, who had sent the girl to one of his ashrams for spiritual lessons, were summoned to see her as she was “under the influence of some supernatural ghostly powers”.
They were then told to take their daughter to Jodhpur to meet the guru.
The family reached the Jodhpur ashram on 14 August. The following night, Asaram called the victim to his room on the pretext of “curing” her. He then raped the victim while her parents waited outside chanting his prayers, police say.
Police say the guru forced the victim to perform sexual acts on him and threatened to murder her family if she spoke about the incident.
The victim told her parents what had happened the following day. They tried to confront Asaram, but were refused entry to his ashrams.
Who is Asaram Bapu?
Asumal Harpalani was born in April 1941 in a village called Bernai in Sindh region in present-day Pakistan.
His family migrated to Ahmadabad city in Gujarat after the partition of India.
In the 1960s, he started practising spiritualism with different gurus – one of whom gave him the name Asaram. He formed his first ashram in 1972 on the banks of the Sabarmati river in Motera town of Gujarat.
His influence spread to different parts of India and around the world in the following decades.
According to his website, he has 40 million followers around the world and has built 400 spiritual retreats across 19 countries.
Important Indian politicians, including Prime Minister Narendra Modi, have attended his sermons in the past.
He also has properties worth millions of dollars across India. The police are also investigating him for corruption and forgery.
Controversies around his trial
Asaram is also accused of raping another woman in Surat city in Gujarat between 2002 and 2004. The trial in this case is under way.
At least nine witnesses in both cases have been attacked over the past five years – three of them have since died.
Police are investigating these attacks.
The victims’ families insist that the guru and his followers are behind these attacks – an allegation he denies.
The Jodhpur rape case, for which he has been convicted, has also seen the victim’s family threatened by his followers.
Other gurus in the news
Asaram is far from being the first self-styled Indian holy man to be accused and found guilty of crimes.
The Hindustan Times lists a string of controversial gurus who have been in the news for the wrong reasons in recent years. Charges have included murder, sexual assault and corruption.
- In 2017, Gurmeet Ram Rahim Singh was convicted and sentenced to 20 years in prison for rape. He has also been investigated for murder and has been accused of forcing followers to undergo castrations to “get closer to god”.
- Baba Rampal is currently in jail facing a number of serious charges, including murder, attempted murder and sedition. He was accused of operating an illegal abortion centre in his ashram where a number of weapons were also confiscated.
- Swami Nithyananda was charged with obscenity after a video apparently showed him engaging in a sexual act with a film actress. He said he was innocent and the video was a fake. He was detained in 2010 but released on bail. He’s still awaiting trial in several cases.
Many Indian spiritual figures have large international followings.
One of the most memorable was Rolls Royce-loving Bhagwan Shree Rajneesh, who died in 1990 and taught his devotees that free love was the path to enlightenment.
A Netflix documentary series recently brought Rajneesh back into the public eye, reminding viewers of the utopian community he set up on an Oregon ranch before it descended into assassination plots and the largest bio-terrorist attack in US history.
He’s now been renamed “Osho”. Tens of thousands of people continue to visit the movement’s centre in Pune in India every year.